1. Field of the Invention
The present invention is in the field of food additives in the form of products which contain extracts of fruits having enlarged concentrations of naturally occurring phenolics. More particularly the present invention is in the field of products and additives to foods which products contain extracts of apples having enlarged concentrations of phenolics. The present invention also relates to the process of obtaining products used as food additives having enlarged concentrations of phenolics, the process involving extraction of phenolics from fruits, particularly from apples.
2. Brief Description of Background Art
It has been known in the prior art that certain compounds or ingredients, present in fruits, particularly in grapes and apples, possess various benefits for human health apart from the well known benefits of vitamins, minerals and other nutrients considered to be the main ingredients of fruits. The terms xe2x80x9cphenolicsxe2x80x9d or xe2x80x9cplant phenolicsxe2x80x9d have been developed and been adopted in the art for a class or type of these compounds because these compounds include in their formula a hydroxyl (OH) function attached to an aromatic carbon atom in analogy to the well known chemical phenol, or these compounds have a chemical structure closely related to or derived from a compound having an aromatic (phenolic) hydroxyl group. Usually plant phenolics have more than one aromatic (phenolic) hydroxyl group. Generally speaking, plant phenolics have antioxidant properties and have been shown in in vitro and in in vivo studies to have positive effects on the human cardio-thoracic condition. The phenolics isolated from fruits, primarily from apples, include gallic acid, flavan-3ols, flavonols, phloridzin, cinnamates, hydroxymethyl furfural and anthocyanins. A publication titled xe2x80x9cVINOX(trademark) (Grape Seed Extract) Technical Publication Ixe2x80x9d by Polyphenolics, Inc., Burlingame Calif., describes the health benefits obtained as a result of consumption of phenolics and related compounds found in grapes and wine (particularly red wine), and identifies by chemical structure several phenolic compounds found in grape seeds. Apples are a rich and well known source for phenolics, and the phenolics are primarily concentrated in the peel. A publication by Pearson et al. titled xe2x80x9cApple Juice Inhibits Human Low Density Lipoprotein Oxidationxe2x80x9d, in Life Science, Volume 64 No. 21, 1999 describes human health benefits provided by the consumption of phenolics in apple juice.
U.S. Pat. No. 5,932,623 describes a process for obtaining extracts from unripe fruits and purports to identify the polyphenol products which are in the extract. U.S. Pat. No. 5,989,557 discloses an extract obtained from tea. U.S. Pat. Nos. 4,156,662 and 5,354,429 relate to extraction of aromas and other chemicals from plants or feed stocks of petroleum processing.
Because of the richness of apples as a source of plant-phenolics and because of the availability of apple peel and core as a relatively economical raw material, efforts in accordance with the present invention to produce isolates containing high concentration of phenolics have been focused on apple peel and apple core serving as a source.
It is an object of the present invention to obtain from fruits, and particularly from apples, an extract which is rich in natural phenolics of the fruit and which is utilized as a supplement or additive in various food products.
It is another object of the present invention to obtain from fruits, and particularly from apples, an extract which is rich in natural phenolics of the fruit and which does not impart an unnatural or undesired taste component to the food product in which it is used. It is still another object of the present invention to provide food products such as beverages, dairy products, frozen products, jams, jellies, preserves, and confectionary products which have an enlarged concentration of phenolics that have been extracted from fruits, particularly from apples, in accordance with the present invention.
The foregoing objects and advantages are attained by a product or products that is obtained by extracting the fruit, or parts of the fruit such as peels and or cores with hot water in a temperature range of approximately 65 to 93xc2x0 C. (150 to 200xc2x0 F.), followed by depectinization of the extract with a pectinase enzyme, preferably at an elevated temperature of approximately 38 to 57xc2x0 C. (100 to 135xc2x0 F.) until test taken for pectin is substantially negative. The pectinase enzyme is then deactivated by heating the mixture to approximately 60 to 93xc2x0 C. (140 to 200xc2x0 F.) and the aqueous solution/suspension is filtered to yield discardable solids and an aqueous filtrate. Polyvinylpolypyrrolidone (PVPP) adsorbent is then added to the filtrate aqueous solution and the mixture is agitated to extract by adsorption of the plant phenolics contained in the aqueous phase. The polyvinylpolypyrrolidone (PVPP) adsorbent containing adsorbed plant phenolics is then collected by filtration, centrifugation or like method. The aqueous filtrate at this stage is substantially devoid of recoverable plant phenolics but after concentration can still serve as useful product, primarily as a delivery vehicle for the plant phenolics obtained by the following additional process steps.
The collected solid polyvinylpolypyrrolidone (PVPP) adsorbent containing adsorbed plant phenolics is then washed multiple times with water to remove solids other than the adsorbed plant phenolics. The plant phenolics are obtained from the PVPP adsorbent by treating the adsorbent with dilute sodium hydroxide (or other acceptable strong base) solution, to give an aqueous extract of the plant phenolics, having a concentration of approximately 400 to 5000 mg gallic acid equivalent per liter (GAE/L) of the extract. The polyvinylpolypyrrolidone (PVPP) adsorbent recovered by filtration can be regenerated for repeated use by careful washing with water until all base is substantially removed from it.
The aqueous extract containing the plant phenolics can be further concentrated to give a liquid product with greater concentration of plant phenolics. Alternatively the aqueous extract is mixed with a nutritionally acceptable carrier, such as maltodextrin, rice dextrin, modified corn starch or other carrier, and the mixture is converted to a solid by spray drying or like drying process effective to yield a solid product. When in a solid form, such as the spray dried product obtained from the aqueous extract, the concentration of phenolics depends on the amount of carrier (if any) or carriers added and on the moisture content of the solid. Preferably the spray dried solid product contains approximately 10 mg or more gallic acid equivalent (GAE) per gram of solid (1% by weight). When the aqueous extract is concentrated but not dried completely, it typically contains approximately 50,000 to 200,000, preferably approximately 100,000 mg GAE/L.
The liquid concentrate, dried solid product or their solutions can be added to diverse types of food products, such as beverages, dairy products, frozen products, jams, jellies, preserves, and confectionary products to provide or enrich the products with fruit phenolics.
The features of the present invention can be best understood together with further objects and advantages by reference to the following description, taken in connection with the accompanying drawings.